In order to display a high-contrast image, reduce power consumption, and so on, it is possible to partially drive an edge light type light source device included in a display device. That is to say, white light introduced into a light guide plate is used and light is emitted partially from the light guide plate. With such a light source device a technique for reducing luminance irregularity or color irregularity which occurs at partial drive time is proposed (see, for example, Japanese Laid-open Patent Publication No. 2012-252835).